DNA analysis Flashcards
What are the four base pairs of DNA?
Adenine, Thymine, Cytosine, Guanine
In which direction do DNA strands duplicate?
5’ - 3’ direction
What percentage of the human genome is coding?
Less than 2%
Where is DNA found in the cell?
Nucleus and Mitochondria
How many pairs of autosomal chromosomes are in each somatic cell?
22 pairs
What is the somatic number represented as?
2n
What are sister chromatids?
Identical copies of chromosomes joined by a centromere
What is one reason individuals show genetic variation?
Genetic recombination
What occurs during meiosis that contributes to genetic variation?
Random assortment of chromosomes
What are barriers to gene flow?
Migration
What is a mutation?
Insertion or deletion of base pairs in DNA
What is a point mutation?
Transversion or transition mutations
What is a DNA profile?
A small set of DNA variations likely to differ in unrelated individuals
What class of molecular markers is used in DNA profiling?
STR (Short Tandem Repeats)
What is genotype frequency?
Proportion of specific genotypes within a population
What is the frequency of allele A1 if p = 0.86?
0.86
What is the frequency of allele A2 if q = 0.14?
0.14
What does a Homozygote 7,7 probability calculation represent?
P = 0.29492
What is the probability of observing a matching profile if the defendant is an 11,11?
1 in 4,000,000
What is an exclusion result in DNA profiling?
It negates the DNA evidence
Name a factor that can lead to matching DNA profiles innocently.
Monozygotic twins
What are the three processes involved in DNA extraction?
Extraction, Purification, Concentration
What is needed for PCR?
Thermal cycler, Template DNA, PCR Primers, DNA polymerase, PCR Buffer
What are the steps in PCR?
Denature, Anneal, Extend
